The number of defects in a bolt of cloth is to be monitored by means of a c chart. Defects include flaws in the weave and irregularities in the dye. Before actually implementing the control chart a trial run using simulated data was carried out. The first 6 observations in the data set below come from a Poisson distribution with parameter λ1 = 6, the next 8 observations come from a Poisson distribution with parameter λ2 = 9, and the final 6 observations come from a Poisson distribution with parameter λ3 = 6.5. Consequently, the simulated data do not come from a process in statistical control. Calculate the three-sigma control limits using and plot the c control chart. Does the control chart detect a lack of control? 1, 5, 6, 7, 3, 6, 11, 9, 8, 10
12, 10, 9, 8, 4, 6, 5, 6, 4, 7
